I changed alternator belts this spring. This weekend it smoked and smelled like burning rubber. It's fairly tight and didn't sound like it was slipping (and I was getting a consistent charge), but I'm not 100% certain. Oddly enough, I had run the engine hard twice before without having this problem - but in both cases the batteries were full, unlike this weekend when they were down. Perhaps this was the first time the alternator was putting any kind of load on the belt. Any suggestions?

Thanks,
Max